1. Field of the Invention
The invention relates to a filter apparatus, more particularly to a composite filter apparatus for replacing filter materials in an independent manner.
2. Description of the Related Art
Referring to FIG. 1, Taiwanese Patent No. 527954 discloses a first conventional filter apparatus 1. The first conventional filter apparatus 1 includes a cylinder body 11, a cylinder lid member 12 that is formed in one piece with the cylinder body 11 for sealing, an one-piece filter core 13 that is mounted below the cylinder lid member 12, and a watering seat 14 that permits water to enter thereto or to exit therefrom.
The cylinder lid member 12 has a protrusive seat 121 that is threadedly connected to the watering seat 14, a water inlet 122 that extends axially through the protrusive seat 121, and a water outlet 123 that extends axially through the protrusive seat 121 and that is distal from the water inlet 122.
The filter core 13 is mounted inside the cylinder body 11 and is connected to a bottom end of the water outlet 123 of the cylinder lid member 12. The filter core 13 has a fine-particle filtration layer 131 (such as a hollow fiber membrane), a rude-particle filtration layer 132 (such as a polypropylene fiber layer) that is sleeved on the fine-particle filtration layer 131, activated carbon particles 133 that are filled in the rude-particle filtration layer 132, and an ion exchange resin layer 134 that is coated on a surface of the rude-particle filtration layer 132 and that is fluid-permeable. Accordingly, the filter core 13 has composite filter materials.
The watering seat 14 has a water-entry opening 141 that communicates the water inlet 122 and a water-exit opening 142 that communicates the water outlet 123.
When the first conventional filter apparatus 1 is used for fluid filtration, the fluid enters the water-entry opening 141, subsequently passes through the water inlet 122 and flows into the cylinder body 11. Then, the fluid passes through the ion exchange resin layer 134, the rude-particle filtration layer 132 with the activated carbon particles 133, and the fine-particle filtration layer 131 in a successive manner. The fluid flows out the water-exit opening 142 through the water outlet 123. However, since the water-entry opening 141 and the water-exit opening 142 are both disposed on the watering seat 14, flowing of the filtered fluid out of the first conventional filter apparatus 1 through the filter core 13 is difficult, and the fluid may not be completely filtered. In addition, since the filter core 13 is configured as one-piece, the filter core 13 has to be entirely replaced even if only one of the filter materials of the filter core 13 needs substitution. As a result, the first conventional filter apparatus 1 may result in relatively high replacement cost and is uneconomical.
Referring to FIG. 2, a second conventional filter apparatus 2 disclosed in Chinese Patent No. ZL200720195995.7 includes an annular body 21, water-entry and water-exit lids 22, 23 that are respectively and threadedly connected to two end sides of the annular body 21, an activated carbon particle filter core 24 that is mounted inside the annular body 21, a polypropylene-thermal sprayed filter core 25 that is bonded to an end portion of the activated carbon particle filter core 24 and that is engaged with a first annular protrusive seat 231 of the water-exit lid 23, first and second polypropylene filter plates 26, 28 that are spaced apart from each other and that are disposed in another end portion of the activated carbon particle filter core 24, and a kinetic degradation fluxion (KDF) filter material 27 that is filled between the first and second polypropylene filter plates 26, 28. The second polypropylene filter plate 28 abuts against a second annular protrusive seat 221 of the water-entry lid 22. The water-entry lid 22 further has a water inlet 222 that is disposed at a central position of the water-entry lid 22. The water-exit lid 23 further has a water outlet 232 that is disposed at an eccentric position of the water exit lid 23. The activated carbon particle filter core 24 has a casing body 241 and activated carbon particles 242 that are disposed inside the casing body 241.
Although the second conventional filter apparatus 2 tries to improve a deficiency that requires the entire replacement of the filter core by means of a multi-layer filter material design, the activated carbon particle filter core 24 has to additionally include the casing body 241 for receiving the activated carbon particles 242, and thus the second conventional filter apparatus 2 has relatively high fabrication cost. In addition, when one of the polypropylene-thermal sprayed filter core 25 and the activated carbon particle filter core 24 needs to be replaced, they have to be replaced together in that they are bonded to each other. As a result, the second conventional filter apparatus 2 may still have relatively high replacement cost and undue wastage.